Add advanced setting for disabling leading wildcards in kuery

docs/management/advanced-options.asciidoc

@@ -22,6 +22,7 @@ compatible with other configuration settings. Deleting a custom setting removes
 .Kibana Settings Reference
 [horizontal]
 `query:queryString:options`:: Options for the Lucene query string parser.
+`query:allowLeadingWildcards`:: When set, * is allowed as the first character in a query clause. Currently only applies when experimental query features are enabled in the query bar. To disallow leading wildcards in basic lucene queries, use query:queryString:options.
 `search:queryLanguage`:: Default is `lucene`. Query language used by the query bar. Choose between the lucene query syntax and kuery, an experimental new language built specifically for Kibana.
 `search:queryLanguage:switcher:enable`:: Show or hide the query language switcher in the query bar.
 `sort:options`:: Options for the Elasticsearch {ref}/search-request-sort.html[sort] parameter.

src/core_plugins/kibana/ui_setting_defaults.js

@@ -18,6 +18,10 @@ export function getUiSettingDefaults() {
       description: '<a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/query-dsl-query-string-query.html" target="_blank" rel="noopener noreferrer">Options</a> for the lucene query string parser',
       type: 'json'
     },
+    'query:allowLeadingWildcards': {
+      value: true,
+      description: 'When set, * is allowed as the first character in a query clause. Currently only applies when experimental query features are enabled in the query bar. To disallow leading wildcards in basic lucene queries, use query:queryString:options',
+    },
     'search:queryLanguage': {
       value: 'lucene',
       description: 'Query language used by the query bar. Kuery is an experimental new language built specifically for Kibana.',

src/ui/public/courier/data_source/build_query/build_es_query.js

@@ -4,7 +4,7 @@ import { buildQueryFromKuery } from './from_kuery';
 import { buildQueryFromFilters } from './from_filters';
 import { buildQueryFromLucene } from './from_lucene';
 
-export function BuildESQueryProvider(Private) {
+export function BuildESQueryProvider(Private, config) {
   const decorateQuery = Private(DecorateQueryProvider);
 
   /**
@@ -16,7 +16,7 @@ export function BuildESQueryProvider(Private) {
     const validQueries = queries.filter((query) => has(query, 'query'));
     const queriesByLanguage = groupBy(validQueries, 'language');
 
-    const kueryQuery = buildQueryFromKuery(indexPattern, queriesByLanguage.kuery);
+    const kueryQuery = buildQueryFromKuery(indexPattern, queriesByLanguage.kuery, config);
     const luceneQuery = buildQueryFromLucene(queriesByLanguage.lucene, decorateQuery);
     const filterQuery = buildQueryFromFilters(filters, decorateQuery, indexPattern);
 

src/ui/public/courier/data_source/build_query/from_kuery.js

@@ -1,14 +1,23 @@
 import { fromLegacyKueryExpression, fromKueryExpression, toElasticsearchQuery, nodeTypes } from '../../../kuery';
 import { documentationLinks } from '../../../documentation_links';
+import { NoLeadingWildcardsError } from '../../../kuery/errors';
 
 const queryDocs = documentationLinks.query;
 
-export function buildQueryFromKuery(indexPattern, queries = []) {
+export function buildQueryFromKuery(indexPattern, queries = [], config) {
+  const allowLeadingWildcards = config.get('query:allowLeadingWildcards');
+
+
+
   const queryASTs = queries.map((query) => {
     try {
-      return fromKueryExpression(query.query);
+      return fromKueryExpression(query.query, { allowLeadingWildcards });
     }
     catch (parseError) {
+      if (parseError instanceof NoLeadingWildcardsError) {
+        throw parseError;
+      }
+
       try {
         fromLegacyKueryExpression(query.query);
       }

src/ui/public/kuery/ast/ast.js

@@ -1,5 +1,6 @@
 import _ from 'lodash';
 import { nodeTypes } from '../node_types/index';
+import * as errors from '../errors';
 import { parse as parseKuery } from './kuery';
 import { parse as parseLegacyKuery } from './legacy_kuery';
 
@@ -27,7 +28,7 @@ function fromExpression(expression, parseOptions = {}, parse = parseKuery) {
 
   parseOptions = {
     ...parseOptions,
-    helpers: { nodeTypes }
+    helpers: { nodeTypes, errors }
   };
 
   return parse(expression, parseOptions);

src/ui/public/kuery/ast/kuery.peg

@@ -1,6 +1,6 @@
 // Initialization block
 {
-  const { parseCursor, cursorSymbol, helpers: { nodeTypes } } = options;
+  const { parseCursor, cursorSymbol, allowLeadingWildcards = true, helpers: { nodeTypes, errors } } = options;
   const buildFunctionNode = nodeTypes.function.buildNodeWithArgumentNodes;
   const buildLiteralNode = nodeTypes.literal.buildNode;
   const buildWildcardNode = nodeTypes.wildcard.buildNode;
@@ -156,6 +156,11 @@ Value
   }
   / value:UnquotedLiteral {
     if (value.type === 'cursor') return value;
+
+    if (!allowLeadingWildcards && value.type === 'wildcard' && nodeTypes.wildcard.hasLeadingWildcard(value)) {
+      throw new errors.NoLeadingWildcardsError();
+    }
+
     const isPhrase = buildLiteralNode(false);
     return (field) => buildFunctionNode('is', [field, value, isPhrase]);
   }

src/ui/public/kuery/errors/index.js

@@ -0,0 +1,10 @@
+import { KbnError } from '../../errors';
+
+export class NoLeadingWildcardsError extends KbnError {
+  constructor() {
+    super(
+      'Leading wildcards are disabled. See query:allowLeadingWildcards in Advanced Settings.',
+      NoLeadingWildcardsError
+    );
+  }
+}

src/ui/public/kuery/node_types/wildcard.js

@@ -33,3 +33,8 @@ export function toQueryStringQuery(node) {
   const { value } = node;
   return value.split(wildcardSymbol).map(escapeQueryString).join('*');
 }
+
+export function hasLeadingWildcard(node) {
+  const { value } = node;
+  return value.startsWith(wildcardSymbol);
+}